Vickers V-1000
The Vickers-Armstrongs V-1000 was a proposed jet-powered cargo aircraft that was designed to meet a requirement issued by the British Ministry of Supply which sought a strategic transport for the Royal Air Force to support its strategic bomber fleet, particularly the V-bombers. The design bears many similarities to the Vickers Valiant, one of the V-bombers, but also featured substantial changes. In addition to its military application, both the Ministry and Vickers also intended to use the same basic design as the VC7, a six-abreast trans-Atlantic jet airliner for British Overseas Airways Corporation.
In 1955, by which point the prototype was already largely complete, the Ministry of Supply decided to terminate the V-1000 project in mid-development. By that time, the design had garnered interest from airlines, and had led to re-designs being conducted by competing US manufacturers, influencing the design of the Boeing 707 and Douglas DC-8. The V-1000 has been called one of the great "what-ifs" of British aviation, and its cancellation was the topic of considerable debate in the House of Commons.
History
Background
During the early 1950s, Britain's civil aircraft industry was releasing and manufacturing a number of competitive and innovative aircraft designs. They include the de Havilland Comet, the world's first jet-powered commercial transport aircraft, the Vickers Viscount, the world's first turboprop-powered commercial airliner, and the Bristol Britannia, a turboprop-powered aircraft capable of conducting routine transatlantic flights. All of those designs had their origins in the specifications laid out by the wartime Brabazon Committee. With those aircraft, Britain appeared to be on track to capturing a large slice of the global demand for civil aircraft for the foreseeable future.Meanwhile, the Royal Air Force had been pursuing development of a new generation of strategic bombers: the Vickers Valiant, the Avro Vulcan, and the Handley Page Victor. Armed with nuclear weapons and powered by jet engines, those aircraft would be entering service during the 1950s as the V-bombers. The first of the V-bombers to enter service was the Valiant. Noting the favourable performance attributes of the Valiant, both the Ministry of Supply and Vickers became interested in a prospective transport derivative, as a potential long-range successor to the smaller Comet. The RAF had also noticed a demand for a suitable transport aircraft capable of accompanying the V-bombers on deployments to any part of the world, carrying a mix of personnel and cargo needed for such deployments, while having similar speed and range capabilities to the bomber force.
Vickers received a request from the MoS for submissions of the Valiant transport derivative. At the same time, the British Overseas Airways Corporation was also interested in a potential commercial airliner from Vickers; thus, the company was naturally excited that it would be possible to develop an aircraft that would serve as both a military transport, being procured for the RAF, and as a commercial airliner, that BOAC would be expected to order. Such a move would mean increased financial support for the program as well as improved access to development and testing resources. According to aviation author Derek Wood, Sir George Edwards, who headed the design, viewed the military variant "as a stepping stone to the civil version", which was internally designated as the VC7.
Working in direct cooperation with BOAC throughout the studies performed for the project, Vickers came to quickly recognise that producing a suitable aircraft would not be a straightforward matter of simply pairing the Valiant's wings onto a new fuselage suitable for transport duties. Amongst the changes required would be an entirely new structure, the adoption of roomy and pressurised cabin, and more powerful engines. RAF requirements also provided some complications for the design, such as necessitating the use of double-slotted flaps to achieve the short field performance sought, along with the integration of a rear-mounted sizable hydraulic freight elevator for self-loading operations. Crucially, it was recognised that, in order for the aircraft to be economically viable against competing aircraft powered by turboprop engines and traditional piston engines, an engine capable of more thrust and superior specific fuel consumption than the Valiant's Rolls-Royce Avon turbojet engine would be necessary.
In October 1952, the MoS formally released Air Specification C.132D for the jet-powered transport. Various firms responded with their own submissions to meet the requirement. Handley Page offered the HP.97, which featured a two-level layout that moved the passenger seating above the wing of a design otherwise almost identical to the Victor. BOAC rejected the design, which led to the more highly modified HP.111, which was similar in layout but had a modern six-abreast single-deck fuselage. Avro started with their Vulcan design, keeping its tailless delta wing and mating it with a new fuselage, producing the Avro Atlantic. As the name implies, the design was specifically intended to offer trans-Atlantic range. Avro boasted that the delta wing offered good takeoff performance without the need for flaps or slats that conventional wings would require, while also offering a high cruising speed. Various versions were offered with 2+2 to 3+3 seating, with the added oddity that the seats faced to the rear of the aircraft.
The initial submission made by Vickers was designated as the VC5, which was essentially a slightly-stretched Valiant bomber with windows. It retained the Valiant's shoulder-mounted wing, which would have left many rows windowless, and also meant that it had long landing gear that BOAC considered unsuitable. Originally designed in the late 1940s, the VC5 attracted little interest and was soon dropped in favour of a more advanced submission by Vickers. Amongst the differences between the VC5 and the VC7 were a larger 12 ft 6 in fuselage with six-abreast seating for 131 passengers, the wings having been relocated to a low-mounted position, the addition of slotted flaps, and the overall size of the wing being considerably larger. As envisioned, the VC7 would not only be capable of flying the traditional Empire routes but also the increasingly prestigious North Atlantic market.
Selection and refinement
In January 1953, Vickers received an order for the production of a flight-capable prototype, later given the serial number XD662, along with a structural test frame. in March 1953, it was revealed that the Vickers design had been selected as the winner of the MoS competition. In June 1954, the Secretary of State for Air William Sidney, 1st Viscount De L'Isle announced that a production order for the military variant, designated as the V-1000, was to be placed for the RAF. Detailed development work on the project started following the issuing of the Specification in October 1952, however it was soon recognised that the V-1000 would be substantially more difficult to develop that any previous transport aircraft that had been operated by the RAF as neither the ministry nor industry were experienced in the development of jet aircraft of this scale before.As a concept, the aircraft was more complex than the Comet, as well as being physically far larger as an aircraft. The strict and detailed requirements of the specification required extensive testing, such as the heavy use of wind tunnels to cover short-field operations in addition to high-speed cruising flight, while structural and system demands took Vickers into uncharted territories and new entirely new fields. While much of the know-how had been derived from the Valiant and there were elements of the design, such as the engines' internal mounting inside the wings, showed this ancestry, areas such as the structure had dramatic differences, the integrity of the cabin and engine bay conforming to fail-safe principles, unlike the preceding Comet. The finalised design for the V-1000 was enlarged beyond that which the RAF had expected; this was so that commonality could be maximised between the VC7 and V-1000; accordingly, the same airframe was to be used for both the civil and military variants.
A key innovation of the V-1000 was its intended use of the Rolls-Royce Conway, which was the first production bypass engine, offering both increased range and improved fuel economy. Rolls-Royce Limited was already developing the Conway engine, having performed its first running in 1950, and had demonstrated the improved fuel consumption of the engine; by 1951, the Conway was being developed for a thrust output of 13,000 lb; enough to serve as the powerplant for the V-1000. However, as the V-1000 design was enlarged beyond its original dimensions, the development of a more powerful model of the Conway was necessitated, contributing to delays on the overall project.
Construction of the prototype was performed at Vickers' facility at Wisley Airfield, Surrey; flight trials would have also been based there. By November 1956, over £4 million had been spent on the V-1000 project; the first prototype had also reached 80 per cent completion. It had been estimated that the VC7 would have been in operational service as early as 1959, the same year in which the first V-1000s were projected to be delivered to the RAF. If it had entered commercial service as envisioned, it would have been the first turbofan-equipped airliner to serve long-haul routes.
The VC7 proved to be of concern to aircraft manufacturers in the United States, where both Boeing and Douglas were in the process of designing their own jet transports to a very similar requirement from Strategic Air Command. Both companies had responded with designs sized for 2+3 seating, providing more limited passenger capabilities than the VC7. Additionally, the VC7's wing design offered a number of advanced features and increased wing area that greatly reduced take-off run and allowed it to operate from a wider selection of airports, while at the same time offering longer ranges. When the US companies approached airlines with their plans, they found that they were constantly rejected as the VC7 was more interesting. Both companies undertook expensive re-designs of their projects to compete, enlarging the fuselage to match the VC7's 3+3 layout and increasing the overall size and weight of their aircraft. When they were re-introduced to the markets in this larger form, the US firms fared considerably better; after an initial order from Pan American Airways, orders started rolling in from around the world. The better range that the VC7 offered took longer to address, and at one point was solved by incorporating the Conway into those designs.